[FEATURE] Multiple citations

[eseiler]

Currently, the citations are a std::string

sharg-parser/include/sharg/auxiliary.hpp

Line 85 in a59e368

std::string citation;

This makes it a bit hard to have multiple citations

LEGAL
    Raptor Copyright: BSD 3-Clause License
    Author: Enrico Seiler
    Contact: [email protected]
    SeqAn Copyright: 2006-2023 Knut Reinert, FU-Berlin; released under the 3-clause BSDL.
    In your academic works please cite: (1) Raptor: A fast and space-efficient pre-filter for querying very
    large collections of nucleotide sequences; Enrico Seiler, Svenja Mehringer, Mitra Darvish, Etienne Turc, and Knut
    Reinert; iScience 2021 24 (7): 102782. doi: https://doi.org/10.1016/j.isci.2021.102782 (2) Hierarchical
    Interleaved Bloom Filter: enabling ultrafast, approximate sequence queries;Svenja Mehringer, Enrico Seiler, Felix
    Droop, Mitra Darvish, René Rahn, Martin Vingron, and Knut Reinert; Genome Biol 24, 131 (2023). doi:
    https://doi.org/10.1186/s13059-023-02971-4
    For full copyright and/or warranty information see --copyright.

It would be nice to have a std::vector<std::string> instead and have the citations nicely formatted.

This would also be an API break. Maybe it's possible to have a struct that

• Behaves like std::string for the old style and issues a deprecation message
• Behaves like std::vector<std::string> if feasible constructors/push_back is used